putting 'Real' Songs on your videos

I have always used songs from the popular music hit parade on my videos whether it be a holiday vid or some other family occasion as I like the words to help the pictures, but now owning a P3P I have a whole new dimension of footage

most drone videos seem to use royalty free instrumentals, which don't get me wrong work on the whole, but I was wondering why this is?

I do know from experience youtube tends not to like it when you do this and they send an email or mute the sound on your video because you do not have the copyright owners permission, mind you this was a year or so ago, do they still do this?

If you use music that belongs to another artist, YouTube will detect this (Shazam-like) and either ;

a) restrict the video from playing in some countries, or
b) let you keep your video and force you to agree to have ads on your clips, proceedings from which (partly anyway)... go to the rights owner of the music.

Yop and they even have more strict rules now than ever. Free Royalty stuff is a bit hard to find on the web. So I make a 5 to 10 min. video using the YT music library then I download it (3rd party) and use the music has I please and put it back on YT.